Complement C3 proteins play a key role in initiating the complement system through processing by C3 convertase in the classical and alternative pathways. Upon activation, C3b covalently binds to the surface, while C3a (anaphylatoxin produced by proteolysis of C3) mediates local inflammation. Complement C3 Protein, Cynomolgus (HEK293, His) is the recombinant cynomolgus-derived Complement C3 protein, expressed by HEK293 , with C-His labeled tag.